Patient and clinical characteristics associated with gout flares in an integrated healthcare system

Comparison of Gout Flares With the Initiation of Treat-to-Target Allopurinol and Febuxostat: A Post-Hoc Analysis of a Randomized Multicenter Trial

OBJECTIVE

Initiating urate-lowering therapy (ULT) in gout can precipitate arthritis flares. There have been limited comparisons of flare risk during the initiation and escalation of allopurinol and febuxostat, administered as a treat-to-target strategy with optimal anti-inflammatory prophylaxis.

METHODS

This was a post-hoc analysis of a 72-week randomized, double-blind, placebo-controlled, noninferiority trial comparing the efficacy of allopurinol and febuxostat. For this analysis, the occurrence of flares was examined during weeks 0 to 24 when ULT was initiated and titrated to a serum urate (sUA) goal of less than 6 mg/dl (<5 mg/dl if tophi). Flares were assessed at regular intervals through structured participant interviews. Predictors of flare, including treatment assignment, were examined using multivariable Cox proportional hazards regression.

RESULTS

Study participants (n = 940) were predominantly male (98.4%) and had a mean age of 62.1 years with approximately equal proportions receiving allopurinol or febuxostat. Mean baseline sUA was 8.5 mg/dl and all participants received anti-inflammatory prophylaxis (90% colchicine). In a multivariable model, there were no significant associations of ULT treatment (hazard ratio [HR] 1.17; febuxostat vs allopurinol), ULT-dose escalation (HR 1.18 vs no escalation), prophylaxis type, or individual comorbidity with flare and no evidence of ULT-dose escalation interaction. Factors independently associated with flare risk during ULT initiation/escalation included younger age, higher baseline sUA, and absence of tophi.

CONCLUSION

These results demonstrate that gout flare risk during the initiation and titration of allopurinol is similar to febuxostat when these agents are administered according to a treat-to-target strategy using gradual ULT-dose titration and best practice gout flare prophylaxis.

Comparative Risk of Gout Flares When Initiating or Escalating Various Urate-Lowering Therapy: A Systematic Review With Network Meta-Analysis

OBJECTIVE

We systematically examined comparative gout flare risk after initiation or escalation of different urate-lowering therapies (ULTs), comparative flare risk with and without concomitant flare prophylaxis, adverse event rates associated with flare prophylaxis, and optimal duration of flare prophylaxis.

METHODS

We searched the Medline, Embase, Web of Science, and Cochrane databases and clinical trial registries from inception to November 2021 for trials investigating adults with gout initiating or escalating ULT. We performed random effects network meta-analyses and calculated risk ratios (RRs) between treatments. Bias was assessed using the revised Cochrane risk-of-bias tool.

RESULTS

We identified 3,775 records, of which 29 publications (27 trials) were included. When compared to placebo plus prophylaxis, the RR of flares ranged from 1.08 (95% confidence interval [CI] 0.87-1.33) for febuxostat 40 mg plus prophylaxis to RR 2.65 [95% CI 1.58-4.45] for febuxostat 80 mg plus lesinurad 400 mg plus prophylaxis. Compared to ULT alone, the RR of flares was lower for ULT plus rilonacept 160 mg (RR 0.35 [95% CI 0.25-0.50]), ULT plus rilonacept 80 mg (RR 0.43 [95% CI 0.31-0.60]) and ULT plus colchicine (RR 0.50 [95% CI 0.35-0.72]). There was limited evidence for other flare prophylaxis and on prophylaxis harms and optimal duration. Primarily because of missing outcome data and bias in the selection of reported results, 71.4% and 63.4% of studies were assessed as high risk of bias for flares and adverse events, respectively.

CONCLUSION

The RR of flares when introducing ULT varies depending on ULT drug and dosing strategies. There were limited data on ULT escalation. Flare prophylaxis with colchicine and rilonacept reduces flare incidence. More research is required on the harms and optimal duration of prophylaxis.

Clustering of gout-related comorbidities and their relationship with gout flares: a data-driven cluster analysis of eight comorbidities

OBJECTIVES

To study the aggregation of multiple comorbidities in people with gout and explore differences in prognosis of gout flares among different subgroups.

METHODS

Hierarchical clustering was performed to identify homogeneous subgroups among 2639 people with gout using eight comorbidities. A one-year follow-up of acute gout flares in 463 of these people was conducted; the incidence and the timing of gout flares in each cluster were assessed to explore prognosis of gout flares. Binary logistic regression was applied to assess factors associated with gout flares.

RESULTS

In baseline study, we identified five subgroups (C1-C5). C1 (n = 671, 25%) was characterized by isolated gout with few comorbidities. C2 (n = 258, 10%) were all obese. Almost all people in C3 (n = 335, 13%) had diabetes (99.7%). All people in C4 (n = 938, 36%) had dyslipidemia. C5 (n = 437, 17%) had the highest proportion of cardiovascular disease (CVD, 53%), chronic kidney disease (CKD, 56%), and cancer (7%). In follow-up study, C5 had the highest incidence (71.9%) and earliest onset (median 3 months) of gout flares. C2 had the lowest incidence (52.1%) and the latest onset (median 10 months) of gout flares. The highest relative risk for gout recurrent was seen for C5 (OR = 2.09). Other factors associated with the risk of gout flares were age at diagnosis of gout, duration of gout, presence of tophi, and smoking ≥ 20 cigarettes/day.

CONCLUSIONS

We clustered people with gout into five groups with varying comorbidities. People with CVD, CKD, and cancer had the highest risk of gout flares and should receive comprehensive care.

The clinical benefits of sodium-glucose cotransporter type 2 inhibitors in people with gout

Gout is the most common form of inflammatory arthritis worldwide and is characterized by painful recurrent flares of inflammatory arthritis that are associated with a transiently increased risk of adverse cardiovascular events. Furthermore, gout is associated with multiple cardiometabolic-renal comorbidities such as type 2 diabetes, chronic kidney disease and cardiovascular disease. These comorbidities, potentially combined with gout flare-related inflammation, contribute to persistent premature mortality in gout, independently of serum urate concentrations and traditional cardiovascular risk factors. Although better implementation of standard gout care could improve gout outcomes, deliberate efforts to address the cardiovascular risk in patients with gout are likely to be required to reduce mortality. Sodium-glucose cotransporter type 2 (SGLT2) inhibitors are approved for multiple indications owing to their ability to lower the risk of all-cause and cardiovascular death, hospitalizations for heart failure and chronic kidney disease progression, making them an attractive treatment option for gout. These medications have also been shown to lower serum urate concentrations, the causal culprit in gout risk, and are associated with a reduced risk of incident and recurrent gout, potentially owing to their purported anti-inflammatory effects. Thus, SGLT2 inhibition could simultaneously address both the symptoms of gout and its comorbidities.

Metabolomics and Machine Learning Identify Metabolic Differences and Potential Biomarkers for Frequent Versus Infrequent Gout Flares

OBJECTIVE

The objective of this study was to discover differential metabolites and pathways underlying infrequent gout flares (InGF) and frequent gout flares (FrGF) using metabolomics and to establish a predictive model by machine learning (ML) algorithms.

METHODS

Serum samples from a discovery cohort of 163 patients with InGF and 239 patients with FrGF were analyzed by mass spectrometry-based untargeted metabolomics to profile differential metabolites and explore dysregulated metabolic pathways using pathway enrichment analysis and network propagation-based algorithms. ML algorithms were performed to establish a predictive model based on selected metabolites, which was further optimized by a quantitative targeted metabolomics method and validated in an independent validation cohort with 97 participants with InGF and 139 participants with FrGF.

RESULTS

A total of 439 differential metabolites between InGF and FrGF groups were identified. Top dysregulated pathways included carbohydrates, amino acids, bile acids, and nucleotide metabolism. Subnetworks with maximum disturbances in the global metabolic networks featured cross-talk between purine metabolism and caffeine metabolism, as well as interactions among pathways involving primary bile acid biosynthesis, taurine and hypotaurine metabolism, alanine, aspartate, and glutamate metabolism, suggesting epigenetic modifications and gut microbiome in metabolic alterations underlying InGF and FrGF. Potential metabolite biomarkers were identified using ML-based multivariable selection and further validated by targeted metabolomics. Area under receiver operating characteristics curve for differentiating InGF and FrGF achieved 0.88 and 0.67 for the discovery and validation cohorts, respectively.

CONCLUSION

Systematic metabolic alterations underlie InGF and FrGF, and distinct profiles are associated with differences in gout flare frequencies. Predictive modeling based on selected metabolites from metabolomics can differentiate InGF and FrGF.

Development and Validation of an Emergency Department Electronic Medical Record Gout Flare Alert

OBJECTIVE

Patients with acute gout are frequently treated in the emergency department (ED) and represent a typically underresourced and understudied population. A key limitation for gout research in the ED is the timely ability to identify acute gout patients. Our goal was to refine a multicriteria, electronic medical record alert for gout flares and to determine its diagnostic characteristics in the ED.

METHODS

The gout flare alert used electronic medical record data from ED nursing notes and was triggered by the term 'gout' preceding past medical history in the chief complaint, the term 'gout' and a musculoskeletal problem in the chief complaint, or the term 'gout' in the problem list and a musculoskeletal chief complaint. We validated its diagnostic properties to assess presence/absence of gout through manual medical record review using adjudicated expert consensus as the gold standard.

RESULTS

In January 2020, we analyzed 202 patient records from 2 university-based EDs; from these records, 57 patients were identified by our gout flare alert, and 145 were identified by other means as potentially having an acute gout flare. The gout flare alert's positive predictive value was 47% (95% confidence interval [95% CI] 34-60%), negative predictive value was 94% (95% CI 90-98%), sensitivity was 75% (95% CI 61-89%), and specificity was 82% (95% CI 76-88%). The diagnostic properties were similar at both institutions.

CONCLUSION

Our multicomponent gout flare alert had reasonable sensitivity and specificity, albeit a modest positive predictive value. An electronic gout flare alert may help enable the conduct of gout research in the ED setting.

Allopurinol adherence, persistence and patterns of use in individuals with diabetes and gout: A retrospective, population-based cohort analysis

OBJECTIVE

There has been growing interest in the potential role for allopurinol to reduce cardiovascular events in people with diabetes. While adherence to allopurinol is poor in those with gout, our aim was to characterize persistence, patterns of use, and predictors of allopurinol use in a population-based cohort of individuals with diabetes and gout.

METHODS

Individuals with diabetes older than 66 (thus eligible for prescription medication coverage) and newly prescribed allopurinol were followed for up to three years in a retrospective cohort study. Allopurinol use patterns were categorized as adherer (used continuously throughout follow-up), interrupter (non-persistent but subsequently resumed), or discontinuer (non-persistent with no subsequent resumption). Main outcomes were allopurinol non-persistence (no subsequent prescription accounting for a grace period), and indicators of gout severity throughout follow-up (prescriptions for prednisone or colchicine, outpatient gout visits, hospitalization/emergency department visits for gout). Outcome frequencies were determined, a multivariable Cox proportional hazards model evaluated associations between predictors and non-persistence, and zero-inflated negative binomial (ZINB) models evaluated associations between allopurinol use pattern and indicators of gout severity.

RESULTS

22,056 individuals were followed for a maximum of 3.0 years (17,410 with 3 years of follow-up). 9092 (41.2%) were non-persistent with allopurinol. Higher risks of non-persistence were associated with female sex (HR, 95% CI: 1.28, 1.23-1.33), dementia (1.23, 1.11-1.35), and an outpatient visit for gout in the prior year (1.19, 1.09-1.29). There were 12,964 (58.8%) allopurinol adherers, 4618 interrupters (20.9%), and 4474 (20.3%) discontinuers. Allopurinol interrupters and discontinuers had indicators of more severe gout over time compared to adherers, including greater odds of being prescribed prednisone.

CONCLUSION

Allopurinol non-persistence and interruptions were frequent in individuals with diabetes and gout and were associated with prescriptions for prednisone. Suboptimal allopurinol adherence may not only increase the risk of gout complications in this population but also potentially diabetes complications through greater prednisone use and its negative effects on glycemic control.

Adherence and Associated Factors of Treatment Regimen in Drug-Susceptible Tuberculosis Patients

Background: Adherence to tuberculosis (TB) drugs is one of the key aspects of global TB control, yet there is a lack of epidemiological evidence on the factors influencing adherence to TB drugs. Thus, this study aimed to explore the adherence and factors associated with adherence among TB patients in South Korea. Methods: We conducted a cohort study using a sampled national healthcare database from 2017 to 2018. Our study population included incident TB patients initiating quadruple or triple regimen who were available for follow-up for 180-days. Adherence was evaluated using the proportion of days covered (PDC): 1) adherent group: patients with PDC ≥80%; 2) non-adherent group: patients with PDC <80%. Kaplan-Meier analysis was conducted to calculate the median time-to-discontinuation in the study population. We calculated the adjusted odds ratios (aOR) with 95% confidence intervals (CI) to assess factors associated with adherence to TB drugs using logistic regression. Results: Of 987 patients, 558 (56.5%) were adherent and 429 (43.5%) were non-adherent, with the overall mean PDC of 68.87% (standard deviation, 33.37%). The median time-to-discontinuation was 113 days (interquartile range 96-136) in the study population. Patients initiating quadruple regimen were more likely to adhere in comparison to the triple regimen (aOR 4.14; 95% CI 2.78-6.17), while those aged ≥65 years (aOR 0.53; 95% CI 0.35-0.81), with a history of dementia (aOR 0.53; 95% CI 0.34-0.85), and with history of diabetes mellitus (aOR 0.70; 95% CI 0.52-0.96) were less likely to adhere to the drug. Conclusion: Approximately 45% of TB patients were non-adherent to the drug, which is a major concern for the treatment outcome. We call for intensified attention from the authorities and healthcare providers to reinforce patients' adherence to the prescribed TB drugs.

Identification of Gout Flares in Chief Complaint Text Using Natural Language Processing

Many patients with gout flares treated in the Emergency Department (ED) often do not receive optimal continuity of care after an ED visit. Thus, developing methods to identify patients with gout flares in the ED and referring them to appropriate outpatient gout care is required. While Natural Language Processing (NLP) has been used to detect gout flares retrospectively, it is much more challenging to identify patients prospectively during an ED visit where documentation is usually minimal. We annotate a corpus of ED triage nurse chief complaint notes for the presence of gout flares and implement a simple algorithm for gout flare ED alerts. We show that the chief complaint alone has strong predictive power for gout flares. We make available a de-identified version of this corpus annotated for gout mentions, which is to our knowledge the first free text chief complaint clinical corpus available.

Comparison of persistence rates between allopurinol and febuxostat as first-line urate-lowering therapy in patients with gout: an 8-year retrospective cohort study

INTRODUCTION/OBJECTIVES

Lifelong urate-lowering therapy (ULT) with xanthine oxidase inhibitors (XOIs), such as allopurinol and febuxostat, is the cornerstone of gout treatment. This study aimed to compare drug persistence between allopurinol and febuxostat as first-line ULT in patients with gout in real practice.

METHOD

In this retrospective cohort study, we evaluated 602 patients with gout in whom allopurinol or febuxostat was newly initiated from December 2011 to November 2018 at a tertiary rheumatology centre. Persistence was defined as the duration from the first description date to the end of treatment with XOIs or the end of the study period (November 2019).

RESULTS

Among the 602 gout patients, the mean age was 60.2 years and 234 (38.9%) patients had tophi. Allopurinol and febuxostat were started in 237 (39.3%) and 365 (60.6%) patients, respectively. During the study period, 282 (46.8%) patients stopped taking XOIs, and the most common reason for XOI withdrawal was poor health literacy (61.3%). The 1- and 5-year persistence rates of XOIs were 67.2% and 40.9%, respectively. In the Kaplan-Meier analysis, persistence rates of allopurinol were significantly lower than those of febuxostat (p < 0.001). In the multivariable Cox regression model, allopurinol use was a significant risk factor for discontinuation of XOIs (HR = 2.01, p < 0.001). In addition, the presence of tophi and symptom duration < 24 months was independently associated with a higher risk of XOI withdrawal.

CONCLUSIONS

Long-term persistence of XOIs was suboptimal, and allopurinol had worse persistence rates than febuxostat among patients with gout. Key Points • Long-term persistence of xanthine oxidase inhibitors (XOIs) as first-line urate-lowering therapy (ULT) among patients with gout was suboptimal, and the major reason for XOI discontinuation was poor health literacy in our study. • We demonstrated that allopurinol had worse persistence rates than febuxostat among patients with gout, suggesting that febuxostat is a better option for long-term ULT in light of medication adherence in a real-world setting. • Patients with gout with tophi and shorter symptom duration were found to be at high risk for poor persistence of XOIs.

Variation in methods, results and reporting in electronic health record-based studies evaluating routine care in gout: A systematic review

OBJECTIVE

To perform a systematic review examining the variation in methods, results, reporting and risk of bias in electronic health record (EHR)-based studies evaluating management of a common musculoskeletal disease, gout.

METHODS

Two reviewers systematically searched MEDLINE, Scopus, Web of Science, CINAHL, PubMed, EMBASE and Google Scholar for all EHR-based studies published by February 2019 investigating gout pharmacological treatment. Information was extracted on study design, eligibility criteria, definitions, medication usage, effectiveness and safety data, comprehensiveness of reporting (RECORD), and Cochrane risk of bias (registered PROSPERO CRD42017065195).

RESULTS

We screened 5,603 titles/abstracts, 613 full-texts and selected 75 studies including 1.9M gout patients. Gout diagnosis was defined in 26 ways across the studies, most commonly using a single diagnostic code (n = 31, 41.3%). 48.4% did not specify a disease-free period before 'incident' diagnosis. Medication use was suboptimal and varied with disease definition while results regarding effectiveness and safety were broadly similar across studies despite variability in inclusion criteria. Comprehensiveness of reporting was variable, ranging from 73% (55/75) appropriately discussing the limitations of EHR data use, to 5% (4/75) reporting on key data cleaning steps. Risk of bias was generally low.

CONCLUSION

The wide variation in case definitions and medication-related analysis among EHR-based studies has implications for reported medication use. This is amplified by variable reporting comprehensiveness and the limited consideration of EHR-relevant biases (e.g. data adequacy) in study assessment tools. We recommend accounting for these biases and performing a sensitivity analysis on case definitions, and suggest changes to assessment tools to foster this.

Prescribing patterns and healthcare costs of gout

OBJECTIVE/METHODS

The Longitudinal Health Insurance Database (LHID) 2010 was used to identify gout cases and their number of gout flares.

RESULTS

Out of 21,376 gout patients, a total of 3561 (16.7%) had frequent gout flares (≥3 gout flares/year). Average all-cause healthcare utilization (35.9 visits vs. 30.7 visits; p < .001) and gout-related utilization (22.7 visits vs. 15.6 visits; p < .001) were higher in frequent gout flare patients than in those with infrequent gout flares. The median gout-related cost (USD $369 vs. $285; p < .001), but not all-cause costs (p = .25), were higher in frequent gout flare patients compared to the infrequent group. Over 55.8% of the flares were treated with colchicine + NSAIDs.

CONCLUSIONS

In conclusion, patients with frequent gout flares had higher healthcare utilization and gout-related healthcare costs. Colchicine + NSAIDs are commonly used therapy for gout flare.

Prognostic factors associated with early gout flare recurrence in patients initiating urate-lowering therapy during an acute gout flare

Lowering serum urate levels below the threshold for crystal formation with urate-lowering therapy (ULT) has been associated with a lower risk for gout flare reoccurrences. However, gout patients on ULT still commonly suffer from recurring gout flares. The purpose of this study was to explore prognostic factors associated with gout flare recurrence within the first 3 months, in gout patients starting ULT during an acute gout flare. Post-hoc analysis of trial data on acute gout patients randomized to either gout flare standard of care or anakinra treatment were used, including baseline demographic, laboratory, clinical, and patient-reported variables, as well as 3-month follow-up data on gout flare recurrences. Only patients starting ULT at baseline were included. Using variable selection based on clinical relevance, univariate, and multivariate binary logistic regression analyses were done to examine predictors of gout flare reoccurrence. A total of 75 patients were included in this study, of which 36 (48%) experienced a gout flare ≤ 3 months post baseline. The multivariate regression analysis revealed that CRP levels > 30 mg/L (OR 9.47) and lack of prophylaxis when starting ULT (OR 11.56) were independently associated with gout flare recurrence. Similar results were found for the univariate regression analyses. Our results show that CRP levels > 30 mg/L and lack of prophylaxis when starting ULT were prognostic factors for early gout flare reoccurrence in patients starting ULT during an acute gout flare. KEY POINTS: • Gout flare recurrences were common within the first 3 months after starting urate-lowering therapy in gout patients. • Intake of prophylaxis when starting ULT had a strong protective effect on gout flare recurrences. • C-reactive protein level > 30 mg/L was an additional prognostic factor for early (≤ 3 months) gout flare reoccurrence in patients starting ULT during an acute gout flare.

Urate-Lowering Therapy in Moderate to Severe Chronic Kidney Disease

CONTEXT

Hyperuricemia is an independent risk factor for progression of kidney disease.

OBJECTIVE

To determine whether lowering serum uric acid level (sUA) to below 6 mg/dL (target) improves mild to moderate chronic kidney disease (CKD) and whether CKD stage influences the benefit of lowering sUA to target.

DESIGN

Retrospective epidemiologic cohort study conducted over 8 years. Estimated glomerular filtration rate (eGFR) was required in the 6 months preceding the index date (defined as first occurrence of sUA < 7 mg/dL), and at least 1 sUA and eGFR were required during follow-up. Patients were urate-lowering therapy (ULT) naïve, aged 18 years or older, and had CKD Stages 2 to 4 at baseline. Health Plan enrollment with drug benefit was required. Exclusions included active cancer, dialysis, or other kidney disease.

MAIN OUTCOME MEASURES

A 30% decrease or 30% improvement in eGFR from baseline.

RESULTS

A total of 12,751 patients met inclusion criteria; 2690 patients received ULT during follow-up and 10,061 did not. Target sUA was achieved in 1118 patients (42%) receiving ULT. A 30% improvement in eGFR was likelier in patients who achieved the target (odds ratio [OR] = 1.78, p < 0.001). Pairwise comparison of CKD stages showed a 30% improvement in eGFR in CKD Stage 2 (OR = 2.26, p = 0.017) and Stage 3 (OR = 2.23, p < 0.001) but not Stage 4 (OR = 1.50, p = 0.081).

CONCLUSION

Patients who achieve an American College of Rheumatology target sUA below 6 mg/dL during ULT have higher rates of eGFR improvement, especially in CKD Stages 2 and 3.

Hyperuricemia and dementia - a case-control study

Background

There is evidence that uric acid may have antioxidant and neuroprotective effects and might therefore alter the risk for neurodegenerative diseases such as dementia. So far, the relation between serum uric acid (SUA) levels or hyperuricemia and dementia remains elusive. Most studies focused on the disease or SUA levels. Effects of anti-hyperuricemic treatment have not been considered yet. This study investigated the association between hyperuricemia and dementia taking into account anti-hyperuricemic treatment.

Methods

We used longitudinal German public health insurance data and analyzed the association between hyperuricemia with and without different treatment options and dementia in a case-control design. Applying logistic regression the analysis was adjusted for several potential confounders including various comorbidities and polypharmacy.

Results

We identified 27,528 cases and 110,112 matched controls of which 22% had a diagnosis of hyperuricemia or gout and 17% received anti-hyperuricemic drugs. For patients with a diagnosis of hyperuricemia we found a slightly reduced risk for dementia (adjusted odds ratio [OR] 0.94, 95% confidence interval [CI] 0.89 to 0.98). The risk reduction was more pronounced for patients treated with anti-hyperuricemic drugs (adjusted OR 0.89, 95% CI 0.85 to 0.94, for regular treatment).

Conclusions

Our results showed a slight reduction for dementia risk in patients with hyperuricemia, both with and without anti-hyperuricemic treatment.

Rate of adherence to urate-lowering therapy among patients with gout: a systematic review and meta-analysis

INTRODUCTION

Reported adherence to urate-lowering therapy (ULT) in gout varies widely (17%-83.5%). Variability may partly be due to different adherence measurement methods. This review aimed to quantify ULT adherence in adult patients with gout.

METHODS

This analysis examined studies in PubMed, Web of Science, CNKI Scholar and WanFang databases from inception to January 2017. Papers were selected by inclusion and exclusion criteria in the context. Random-effect meta-analysis estimated adherence.

RESULTS

22 studies were found by the inclusion criteria, which involved 1 37 699 patients with gout. Four ways to define adherence were reported. Meta-analysis revealed that the overall adherence rate was 47% (95% CI 42% to 52%, I²=99.7%). Adherence rate to ULT was 42% (95% CI 37% to 47%, I²=99.8%) for prescription claims, 71% (95% CI 63% to 79%) for pill count, 66% (95% CI 50% to 81%, I²=86.3%) for self-report and 63% (95% CI 42% to 83%, I²=82.9%) for interview, respectively. The influential factor on adherence rate was country of origin.

CONCLUSIONS

Among adult patients with gout, overall adherence rate to ULT was as low as 47%, which suggested that clinicians should pay more attention to medication adherence in patients with gout to effectively improve adherence to ULT.

Design and Rationale for the Veterans Affairs "Cooperative Study Program 594 Comparative Effectiveness in Gout: Allopurinol vs. Febuxostat" Trial

BACKGROUND

Gout patients do not routinely achieve optimal outcomes related in part to suboptimal administration of urate lowering therapy (ULT) including first-line xanthine oxidase inhibitors allopurinol or febuxostat. Studies leading to the approval of febuxostat compared this agent to allopurinol in inappropriately low, fixed doses. We will compare allopurinol with febuxostat in gout using appropriately titrated doses of both agents and a "treat-to-target" strategy congruent with specialty guidelines.

METHODS

We have planned and initiated the Veterans Affairs (VA) Cooperative Study Program (CSP) 594, Comparative Effectiveness in Gout: Allopurinol vs Febuxostat study. This large double-blind, non-inferiority trial will enroll 950 gout patients randomized to receive allopurinol or febuxostat. Patients will be followed for a total of 72 weeks encompassing 3 distinct 24-week study phases. During Phase I (0-24 weeks), participants will undergo gradual dose titration of ULT until achievement of serum uric acid (sUA) <6.0 mg/dL or <5.0 mg/dL if tophi are present. Dose escalation will not be allowed during final three study visits of Phase 2 (24-48 weeks) and during Phase 3 (48-72 weeks). The primary study outcome is the proportion of participants experiencing at least one gout flare during Phase 3. Subsequent to the 72-week study, participants will be followed passively for up to 10 years after the study to assess long-term health outcomes.

CONCLUSION

With its completion, the VA Comparative Effectiveness in Gout: Allopurinol vs Febuxostat study will demonstrate the central role of gradual ULT dose escalation and a treat-to-target strategy in gout management.

What Is the Evidence for Treat-to-Target Serum Urate in Gout?

PURPOSE OF REVIEW

Most current clinical guidelines for gout management advocate a treat-to-target serum urate approach, although notable differences exist. Serum urate is a rational target for gout treatment given the central role of urate in disease causality, its association with key outcomes and its practicality of use in clinical practice. This review analyses the evidence for this strategy in gout.

RECENT FINDINGS

Recent studies have confirmed the efficacy of urate-lowering therapy in achieving serum urate targets, both in trials using fixed doses and those applying a treat-to-target strategy. In a limited number of long-term studies (> 12-month duration), interventions that incorporate a treat-to-target serum urate approach have been shown to promote regression of tophi, reduce the frequency of gout flares and improve MRI-detected synovitis. A strong case can be made for a treat-to-target serum urate strategy in gout, supported by existing knowledge of disease pathophysiology, outcomes from urate-lowering therapy studies and emerging results of randomised strategy trials of sufficient duration.

Longitudinal transition trajectory of gouty arthritis and its comorbidities: a population-based study

The aim of the study was to investigate the longitudinal transition trajectory of gout and its comorbidities in male patients with gout in different age groups. A total of 3973 male patients who received a new diagnosis of gouty arthritis were identified from the Taiwan Longitudinal Health Insurance Database and divided into two age cohorts (<50 and ≥50 years). Each patient was individually followed from 2000 to 2009 to identify associated comorbidities, namely hypertension, hypercholesterolemia, diabetes mellitus, cardiovascular diseases, and chronic kidney disease. Two outcome measurements of stroke and all-cause cancer were further identified until 2010. The transition trajectory was divided into the following five phenotype groups: persistent hypertension combined with a high prevalence of various gout-related comorbidities, persistent hypercholesterolemia combined with a moderate prevalence of various gout-related comorbidities, persistent low prevalence of various gout-related comorbidities, moderate to high prevalence of various gout-related comorbidities, and low to high prevalence of various gout-related comorbidities. Although the younger and older patients had a similar longitudinal transition trajectory of gout-related comorbidities, the older patients had a higher 10-year likelihood of transition from a low or moderate to a high prevalence of various gout-related comorbidities. In addition, the incidences of stroke and all-cause cancer were higher in the groups with high and moderate to high prevalences of various gout-related comorbidities than in the other groups. The occurrence of gouty arthritis in different life stages can cause cluster effects involving varying degrees of comorbidities over time. The findings of the current study can provide additional knowledge and increase clinical awareness regarding the early assessment and management of gout-related comorbidities in clinical practice.